Page 37 - Pharmaceutical_Analytical_Chemistry_1_Theoretical_Notes_Level_1

Mansoura National University
Pharm D-Clinical Pharmacy Program Level 1 Pharm. Anal. Chem. 1 (PC 101)

Chemical Equation

❖ Every chemical change in ionic reactions can be represented by a chemical equation.

❖ There are three types of chemical equations:

1) Molecular equation AgNO3(aq) + NaCl (aq) → AgCl (s) + NaNO3(aq)

-
+
-
+
+
-
2) Ionic equation Ag (aq) + NO3 (aq) + Na (aq) + Cl (aq) → AgCl (s) +Na (aq) + NO3 (aq)
-
+
3) Net Ionic equation Ag (aq) + Cl (aq) → AgCl(s)

➢ The ions which do not participate in chemical reactions and
present the same on both sides of the reactions.

Spectator ions (They appear on both sides of the arrow exactly the same way)
+
-
+
+
-
-
Ag (aq) + NO3 (aq) + Na (aq) + Cl (aq) → AgCl (s) +Na (aq) + NO3 (aq)
In other words, they “spectate” or “watch” the other ions react in
an aqueous solution (when the solvent is water).

❖ It is the most precise representation of what actually happens because
Net Ionic + -
Na and NO on each side do not actually undergo any change and
equation 3
are called spectator ions.

➢ Ions that disappear from the net ionic equations.
Spectator ions

Q. The spectator ion(s) in the reaction of AgNO3 with MgCl2 ………..

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